3D printed chitosan-based flexible electrode with antimicrobial properties for electrical stimulation therapy in wound healing

Enhanced bioelectrical stimulation near wound sites plays a crucial role in promoting the wound healing cascade, such as, supporting regular collagen deposition, proper extracellular matrix (ECM) remodeling. This study presents an antimicrobial porous flexible hydrogel electrode (APFE) for personalized electrical stimulation (ES) therapy, targeting infected diabetic wound healing. The APFE addresses these limitations by combining the antimicrobial properties of quaternary ammonium-modified chitin with the conductive polymer PEDOT: PSS, creating a flexible, wound-conforming electrode. Fabricated using 3D printing technology, the APFE can be tailored to conform to the unique anatomical contours of a patient’s wound, thereby enhancing its ability to support cell migration and proliferation– critical processes that ultimately accelerate wound healing. Characterization studies show that the APFE exhibits a tensile strength around ≈2.43± 0.57 MPa, and a stretchability of approximately ≈48.91 ± 2.84 %, closely matching skin flexibility (54 ± 17 %). The electrode’s porous and hydrophilic structure enhances moisture retention, making it suitable for diverse wound environments. In vitro results demonstrated good cell viability and around 85.71 % and 93.65 % bacterial inhibition for pathogens like Methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli) respectively in APFE 3. In vivo studies using infected diabetic mouse wounds demonstrated accelerated wound closure approaching 98.99 % in APFE 3 by Day 14, compared to 79.53 % in controls. Histological analysis confirmed increased re-epithelialization and collagen deposition, key histopathological markers of tissue regeneration, drive improved repair mechanisms and ultimately promote wound healing. These results reinforce the potential of the APFE as a customizable, scalable solution for diabetic wound care.